Does your hospital or institution have an ASP, which oversees ID docs, and if so, does the ASP have the authority to refuse an antibiotic prescribed by an ID consultant?  

ASPs are common place. The studies supporting ASPs oversaw doctors, not specifically trained in Infectious Diseases. However, several institutions have used ASPs to restrict or block abx prescribed by ID docs. Typically and ironically, PharmDs make these recommendations or decisions after reading the ID consultant's notes. Each ASP has a titular ID doc at the head of the committee, but rarely is the ID doc "in charge" of the ASP involved in the decisions to block an abx order. Essentially, such ASPs are implying that ID board certification means little.